I've come to accept that the state of the art of more complex parts (FPGAs, CPLDs, codecs etc. ) is always changing and thus have short lifespans. Seems like all we get at work is around 3 years before the EOL / last buy notices come around. But we're talking about a simple, discrete fet with a myriad of applications. Some parts you just don't stop making, and this is one of them.

I don't want to trivialize the complexity of manufacturing these devices because I certainly couldn't build one in my garage, but they're simple parts in the grand scheme. I sincerely doubt any company with experience in semiconductor manufacturing like Linear would have any trouble building these parts and doing so profitably, and looking back over 4+ years of promises by Linear to deliver these parts is just ridiculous, as is the fact that Linear is the only company apparently trying.

Someone / everyone is missing out on a business opportunity, and people here seem to believe it's a hugely profitable opportunity: building and selling discrete Pchannel JFETs like the 2SJ74.

The weird thing is, Texas Instruments and Linear Technology and Analog Devices have all been building and selling huge volumes of ultra low-noise Pchannel JFETs for 30 years - as the input transistors of their FET input opamps! Take a look at the TL071 or the LME49880 or the AD8067 or LT1464. What do you see connected to the VIN+ and VIN- pins? Pchannel JFETs!

Why oh why have all three companies steadfastly refused to offer these as discrete devices? Or even as matched pairs, which Analog Devices already sells ? Is it possible that they know less about this business opportunity, than DIYaudio knows? Is it possible that they know more?

Folks might do well to realize that the market for DIY parts is in reality extremely small. Insufficient to pay the overheads on even a single fab line for JFets... if you *had* such a thing.

The reason that all of these mfrs are either going boots up or shutting down EOL for through hole components is that their main sources of revenue, the manufacture of *millions* of consumer devices has gone away, going from through hole to almost entirely surface mount. There is no way to push the tide back.

What remains as a question is if there are any "white knights" (like Onsemi) who want to start up a company, *maybe* get to buy the key elements of various desirable devices and make a go of a very very small manufacturing company. But realize that the prices per device are no longer likely to be as they once were - like they were at $1.00 or less per device.

_-_-bear

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_-_-bear http://www.bearlabs.com -- Btw, I don't actually know anything, FYI -- every once in a while I say something that makes sense... ]

The manufacturers are looking for certain sales numbers each quarter. If a part doesn't sell, it gets cut. Even certain voltage zener diodes are becoming obsolete. Sometimes it's just the thru hole version that gets the axe.

The manufacturers are looking for certain sales numbers each quarter. If a part doesn't sell, it gets cut. Even certain voltage zener diodes are becoming obsolete. Sometimes it's just the thru hole version that gets the axe.

What Linear Systems does mostly is license and make discontinued part numbers which were discontinued by larger manufacturers. How would they know how well they'll sell if they don't make them? They've been making the LSK170 for 5 years and going to trade shows etc. Why would they not make the complementary part?

What Linear Systems does mostly is license and make discontinued part numbers which were discontinued by larger manufacturers.

That's quite a different business than the big Semi companies are in. Getting a process running in a different fab with different equipment is not a simple task. A company like Linear would have many different processes and could take considerable time to get it right. My guess would be that the resources necessary to get it right keep getting pulled off the project to work on more profitable parts.

Quote:

Originally Posted by labjr

How would they know how well they'll sell if they don't make them?

They probably have Toshiba's numbers. If someone at a trade show comes up and says here's a PO for a million parts, that will get their attention.